Drone Spraying in Plymouth County, Iowa for Corn and Soybeans

Drone spray rates for Plymouth County fields

Drone spraying in Plymouth County, Iowa is priced per acre for one pass, application only. Plymouth farms average 423 acres and grow more than 440,000 acres of corn and soybeans between them. Rates are set for that scale, from 40-acre river-bottom fields along the Floyd to full quarters on the uplands around Remsen.

Service	Typical rate	Notes
Corn and soybean herbicide	from $11/acre	Post-emerge, 2–3 gallons per acre
Corn fungicide	from $12/acre	Tassel through early grain fill
Soybean fungicide or insecticide	from $12/acre	R3 timing, no wheel tracks
Alfalfa insecticide	from $11/acre	Between cuttings
Cover crop seeding	from $14/acre	Into standing corn or soybeans

Product is billed separately, or the grower supplies it. Iowa State University's 2026 custom rate survey puts drone spraying at $12.50 per acre on average, with a median of $12 and a range of $8–16. Operator listings around Plymouth County run $8–18. Rates here sit at or just under the ISU median. The quote depends on water volume, crop height, field shape, terraces and waterways, obstacles such as power lines and wind turbines, and travel distance. The minimum charge is $250 per visit.

Plymouth County: third in Iowa for farm sales

Measure	Plymouth County, IA (2022 Census)
Farms / land in farms	1,285 farms / 544,068 acres
Market value of sales	$1.117 billion, 3rd in Iowa, 45th in the US
Livestock share	64%
Hogs	$458.1M, 4th in Iowa, 6th in the US
Grains and oilseeds	$405.7M, 4th in Iowa
Cattle	$152.2M, 5th in Iowa
Milk	$98.5M, 5th in Iowa

Le Mars, the county seat, calls itself the Ice Cream Capital of the World because of Wells Enterprises and its Blue Bunny brand. Behind the ice cream is a livestock county. Corn and soybean fields here are often fertilized with manure from hog barns and feedlots, and many operations also grow alfalfa for cattle and dairy. That mix of livestock and crops shapes the spray calendar.

Drone, sprayer or airplane on Plymouth County acres

• Self-propelled sprayers are efficient on dry upland ground in May and June. After a wet spring on Floyd and Big Sioux bottoms, or once corn passes tassel, they struggle.
• Airplanes cover large blocks fast. Around the wind farm near Remsen, and near farmsteads, they have to work around turbines, towers and buildings.
• Drones fly 8–15 feet above the crop, follow terraces in the Loess Hills edge, and can stop short of waterways and buffer strips. They also treat hot spots without spraying the whole field.

Soybean gall midge in Plymouth County

Plymouth was among the first 12 Iowa counties with confirmed soybean gall midge in 2018, alongside neighbors such as Woodbury and Cherokee. By 2025 the pest had been confirmed in 56 Iowa counties. Larvae feed at the base of soybean stems, and injury shows up first on field edges next to last year's soybean ground. Insecticide timing is narrow and depends on adult emergence. Watch ISU's emergence network, then make a quick drone pass along the edges of the field when adults are flying.

Tar spot and corn fungicide timing

Tar spot moved across Iowa to the state's western border within a few years of its arrival. Northwest Iowa growers now scout for it every summer, along with gray leaf spot. A fungicide decision is usually made between tassel and early grain fill, based on ear-leaf lesions, hybrid ratings and the weather outlook. At that stage the corn is over 8 feet tall. A drone flies above the tassels and puts fungicide on the upper canopy without running down rows, which matters most on high-yield manured fields.

Waterhemp: the main weed in northwest Iowa

ISU's Region 1 crop reports, which cover Plymouth County, named waterhemp as the top pest in 2025, while disease and insect pressure stayed low that year. Suspected dicamba-resistant waterhemp has been reported in Iowa since 2023. ISU's program advice is layered residuals and several effective herbicide groups per season. Drones fit the follow-up pass: a post-emerge herbicide on escapes in soybeans after canopy, or a spot treatment along field edges where waterhemp seeds in.

Cover crop seeding and Iowa cost-share

Flying cereal rye or oats into standing soybeans at leaf yellowing, or into corn before harvest, gives cover crops weeks of extra fall growth. In 2026, IDALS cost-share pays $30 per acre for first-time cover crop users and $20 per acre for returning users, up to 160 acres. A crop insurance discount of $5 per acre is also available. Drone seeding works on terraces and waterways a ground seeder skips, and on manure-applied fields that are too soft to drill.

Big Sioux, Floyd River and the Loess Hills edge

The Big Sioux River forms Plymouth County's western border with South Dakota. In 2024, floods near Akron ran about 5 feet above historic high-water marks. The Floyd River runs 112 miles past Le Mars, Merrill and Hinton, and the West Branch Floyd joins it at Merrill. Iowa DNR lists the Floyd from that confluence to Alton as impaired for aquatic life.

The Loess Hills begin in Plymouth County, and the county's western townships climb into steeper ground. Fields beside the rivers and in the hills need label setbacks, careful droplet size, and wind blowing away from water and timber.

Wind turbines and airspace

• Plymouth Wind Energy Center: 73 turbines southeast of Remsen, about 200 MW, online since January 2022. A second phase is in design. Each turbine is mapped as a no-fly obstacle.
• Le Mars Municipal Airport: about 2 nautical miles southwest of downtown. Fields near it need airport awareness.
• Sioux Gateway Airport: south of Sioux City in Woodbury County, home to the 185th Air Refueling Wing's KC-135s. Fields in southern Plymouth County near its airspace need FAA authorization checks.

IDALS licensing and Iowa's bee rule

Iowa's Department of Agriculture and Land Stewardship lets drone applicators qualify in two ways: the full Category 11F aerial exam, or the core exam plus a crop category (1A, 1B or 1C) and Category 11R. The company also needs:

1. An Iowa commercial pesticide company license.
2. Insurance with a comprehensive chemical liability statement.
3. Secondary containment for bulk product, or an exemption.
4. Iowa DOT aircraft registration for each drone, on top of FAA registration.

Out-of-state firms need an Iowa aerial consultant, certified in Category 11, who works for a firm with a physical place of business in Iowa. Pilots also need FAA Part 107 and Part 137 certificates, and a Section 44807 exemption for drones of 55 pounds or more.

Iowa's bee rule bars commercial applicators from applying bee-toxic pesticides to blooming crops between 8 a.m. and 6 p.m. within one mile of a registered apiary. Hives are registered through FieldWatch BeeCheck, and operators check the map before every job.